Passive Pressure II

Q. A retaining wall of height 8 m retains dry sand. In the initial state, the soil is loose and has a void ratio of 0.5, ${\gamma }_d=17.8kN/m^3$ and $\varphi ={30}^{\circ }$, Subsequently, the backfill is compacted to a state where void ratio is 0.4, ${\gamma }_d=18.8kN/m^3$ and $\varphi ={35}^{\circ }$, The ratio of initial passive thrust to the final passive thrust, according to Rankine's earth pressure theory, is

1. 0.38
2. 0.64
3. 0.77
4. 1.5

Q. If the coefficient of active earth pressure is 1/3, then what is the value of the coefficient of passive earth pressure?

1. 1/9
2. 1/3
3. 3
4. 1

Q. The wall friction of the retaining wall

1. decreases active earth pressure but increases passive earth pressure
2. decreases passive earth pressure but increases active earth pressure
3. decrease both active and passive earth pressure
4. increase both active and passive earth pressure

Q. Assertion (A): Passive earth pressure is always greater than the earth pressure at rest and active earth pressure.
Reason (R): In passive state the structure becomes the actuating element and soil becomes the resisting element to maintain the stability.

1. both A and R are true and R is the correct explanation of A
2. both A and R are true but R is not a correct explanation of A
3. A is true but R is false
4. A is false but R is true

Q. Consider the following statements regarding Coulomb's theory of earth pressure:

1. It is based on wedge theory of earth pressure.
2. It assumes the wall surface to be rough.
3. It may or may not satisfy the static equilibrium condition occurring in nature.

Which of these statements are correct?

1. 1, 2 and 3
2. 1 and 2 only
3. 2 and 3 only
4. 1 and 3 only

Q. The 3m high vertical earth retaining wall retains a dry grannular backfill with angle of internal friction of ${30}^{\circ }$ and unit weight $20KN/m^3$. If the wall is prevented from yielding (no movement) the total horizontal thrust (in KN per unit length) on the wall is

1. 0
2. 30
3. 45
4. 270

Q. In a cohesionless soil deposit having a unit weight of $1.5t/m^3$ and an angle of internal friction of ${30}^{\circ },$ the active and passive lateral earth pressure intensities $\left(int/m^2\right)$ at a depth of 10 m will, respectively, be

1. 15 and 5
2. 5 and 15
3. 10 and 20
4. 20 and 10

Q. For a sand having an internal friction of ${30}^{\circ },$ the ratio of passive to active lateral earth pressure

1. 1
2. 3
3. 6
4. 9

Q. Which one of the following typical pressure distribution diagrams represents the lateral pressure distribution on braced sheeting in stiff clay with temporary support, as given by Tschebotarioff?

1. 
2. 
3. 
4. 

Q. Earth pressure and resultant possibilities of wall movement are shown in the diagram below.

The point marked $X$ in the diagram denotes

1. earth pressure at rest
2. active earth pressure
3. arching active pressure
4. passive earth pressure

Q. The retaining wall of height 6 m moves towards right. The thrust on the wall per meter length of retaining wall (upto 2 decimal places) is in kN

1. 612 kN
2. 479 kN
3. 832 kN
4. 1134 kN